Sectional form for construction of concrete culverts, sewers, flumes, and similar arched structures.



F. 1. BULL. SECTIONAL FORM FOR CONSTRUCHON 0F CONCRETE CULVERTS, SEWERS, FLUMES, AND

slMlLAR ARCH ED STRUCTURES.

Patented Dec. 4,1917.

2 S EET APR ll. 19]

APPLICATION FILED F. J. BULL. SECTjONM. FORM FOR CONSTRUCTION OF CONCRETE CULVERTS,-SEWERS, FLUNIES, AND

. v SIMILAR ARCHED STRUCYURES. 1,249,084.

APPLICATION HLED APR-1|. IBIS- Patented D90. 4, 1917.

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Tdall whom it may concern."

Be it known-that I, FRANK J. BULL, a citizen ofthe United States, residing at Fort Collins, in the county of Larimer and State of Colorado,; have invented certain new and useful Improvements in Sectional,

Forms for Construction of Concrete Culverts, Sewers, Flumes, and Similar Arched Structures; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification.

This inventionrelates to improvements in collapsible forms for use in the formation of concrete culverts, sewers, fluines and similar arched or vaulted structures.

"The principal objects of the invention are to provide a form of simpleand inexpensive construction which may be readily and strongly set up and quickly and easily collapsed and removed from the molded structure; and which, when not inuse, may be packed into relatively small space to pro mote convenience and economy in storage or transportation. j v i The invention consists in certain novel features of structureand combination which will appear as the description proceeds.

An'embodiment of the invention is shown in the accompanying drawings, wherein Figure l'is ace1'1tr'al longitudinal "sec tional viewshowing the form as in use;

Fig; 2 is a crosssectional view;

"Fig. sis a cross sectional view but showing the form collapsed and ready for re= movalffromthe molded structure; V Figs14 and 5 are'detail plan viewsof the transverse spreadersfor the side walls;

Fig.6 is a partialplan view" of oneof the base boards, the" other one beingsimilar in construction. Similar characters of reference "designate corresponding parts throughout the several views The form as shownand preferredconsists oftwo sidewalls 1, a top wall 2 bridging the sidewalls, two base boards 3,one'for each sidewall, and a series'of spreaders Each side "wall is preferably made of longitudinal planks braced and connected by Specification of Letters Patent.

Application filed April 11, 1916. Serial No. 90,413.

internally arranged vertical bars 5. The top wall 1s similarly made of longitudinal planks braced and connected by internally arranged cross bars 6. The bars 5 are in the same transverse planes as the respective bars 6 or certain of them; and the upper ends of the bars 5 provideseatings for the top wall 2 when the form is in use, for this purpose fitting in rabbets .7 at the ends of thebars 6.

Each base board 3 has along its upper face and inner edge an angle iron track rail 8 and at the side of said rail a pair of relatively short raised blocks 9 arranged at a suitable interval. The upper faces of the blocks 9 incline laterally downward toward the rail 8 and extend to a similarly inclined face 10 of the board 3, the face 10 being continued throughout the length of said board. The base boards 3 have secured to their outer faces upwardly projecting side plates 11 whose upper edges fit in rabbets 12 of the lowermost planks of the side walls 1, the plates 11 completely closing and sealing the space between the side walls 1 and the base boards 3.

Each side wall 1 is provided along its under face with casters 13 which, when the form is in use, rest upon the blocks 9 of the adjacent base board as shown in Fig. 2. The side wallsthen have a parallelrelation in planesperpendicular to the base or bottom of the molded structure and are held in this relation by the spreaders 4.

The Spreaders l correspond in number tothe bars '5 between theseveral'pairs of which they extend. Each spreaderd con sists of sections connected by a central vertical hinge 14; and itssections maybe ex tended into alining or co-planar relation as shown in Figs. 2 and fl or they may be folded toward one another as shown in Figs; 3 and 5. In use,the Spreaders 4%, extended as in Fig. l rest upon'therails 8 and their ends engage the bars 5. In this way the spread ers rigidly brace the lower portions of the side walls against inward collapse and, in conjunctionwith the cross bars f the top wall 2, hold the side wallsin parallel re. lation; i i i To provide for the'ready and simultaneous disengagement of the spreaders l from the side walls the spreaders are connected by a cable 15, rigidly associated with a section of each spreader and operable,

when pulled, to'effect the simultaneous folding of all the spreaders. In connection with the folding of the spreaders their ends disengage the rails 8 and the spreaders drop between the base boards 3 upon the bottom or base of the molded structure as shown in Fig. 3.

To provide for the support of the top wall from the side walls and for the separate withdrawal of the top wall from the molded structure the cross bars 6 carry a pair of longitudinal parallel rails 16 which adjoin the rabbets 7 and when the form is collapsed rest upon supporting rollers 17 arranged at suitable intervals on each side wall. The rollers 17 are mounted on brackets 18 which are preferably vertically hinged or pivoted to certain of the bars 5 whereby they may be folded inward (2'. 6., toward or against the planks of the side walls) as shown in Fig. 1 so as not to interfere with the stacking of the parts of the form. The brackets 18 are set at such angles that the rollers 17 are suitably spaced from the rails 16 when the form is set up as shown in Fig. 2 but when the form is collapsed and the side walls are moved toward one another as shown in Fig. 3, the rollers 17 come into supporting engagement with the rails 16.

The upper planks of the side walls are rounded near their upper edges whereby their outer faces meet the upper face of the top wall in regular curves whose radii are approximately equal to or very slightly less than the distance between the meeting edges of the side and top walls and the upper outside corners of the rails 16. In this way the side walls, in the collapse of the form, fulcrum about the rails 16 and immediately become loose from the top wall and the adjacent molded structure. The bars 5 engage the upper outside corners of the rails 16 as fulorums, the outer faces of said rails being suitably chamfered as at 19 to provide for the inward movement of the side walls.

The concrete bottom is first formed and thereupon the base boards 3 are placed in position on said bottom, said base boards being arranged in parallel relation and at the correct distance from one another. The side walls are then placed in position, temporary retaining blocks (not shown) being placed at intervals between their lowest planks and the adjacent angle rails 8 and temporary braces (not shown) being interposed between their upper planks. The spreaders A are then placed in position, as shown in Fig. 2 and the temporary retaining blocks and braces are removed. The form is now ready for the top wall which is fitted in position between the side walls with its cross bars 6 engaging the upper ends of the bars.5 as supports.

When the molded structure has become sufficiently set the form may be collapsed. For this purpose the spreaders 4 are disengaged from the side walls by breaking them at their hinge joints whereby said spreaders have the relation and position shown in Fig. 3. Thereupon a slight lateral pull is applied to each side wall in consequence of which the side walls are loosened and roll inward on their casters 13 toward the rails 8 by which their inward movement is arrested. The side walls in their rolling movements fulcrum about the rails 16 as above explained and ultimately bring their rollers 17 into supporting engagement with said rails, the top having in the meantime moved downward from the top of the molded structure to the degree permitted by the described inward movement of the side walls.

The form. thus collapsed may be readily withdrawn by the separate withdrawal of its various parts. In removing the form the top wall is rolled from between the side walls, being supported the while by the rollers 17; the side walls are rolled on their casters 13 from the base boards 3; and the base boards and spreaders are then pulled along the bottom or base of the molded structure until they are completely withdrawn.

The walls of the form may be treated in any suitable manner to prevent theiradherence to the cement or absorption of moisture; and where a number of the forms are arranged in alinement, they may each be provided at one end with thin. metal projections 20 to overlay the end ofan adjoining form.

I claim 1. A collapsible form of the type described comprising parallel base boards, side walls mounted on rollers andsupported on said base boards, and a top wall separably supported by and between said side walls and slidable lengthwise of the side walls for removal from the molded structure. V

2. A collapsible form of the type described comprising parallel base boards, side walls mounted on rollers and supported on said base boards, a top wall separably-supported by and between said side walls, parallel longitudinal rails carried by said top wall and rollers carried by said side walls for supporting engagement with said rails in the collapse of the form. i

3. A collapsible form of the type clescribed comprising parallel base boards having longitudinalrails along their inner edges and havingupper surfaces inclined laterally downward toward said rails, side walls mounted on casters and supported on said base boards and a top wall separably supported by and between said side walls and having elements about which said side walls fulcrum in the collapse of the form.

4. A collapsible form of the type described comprising parallel base boards, side walls supported on said base boards for movement longitudinally thereon and a top wall separably supported by and between said side walls and slidable relathe form the side walls and top wall being separable from each other, and means for supporting said top wall for movement longitudinally on said side walls.

6. A collapsible form of the type described comprising parallel side walls and a top wall separably supported by and between said side walls for movement longitudinally thereon.

7. A collapsible form of the type described comprising parallel side walls, a top wall separably supported by and between said side walls, parallel longitudinal rails carrie'dby said top wall and rollers carried by said side walls for supporting engagement with said rails in the collapse of the form.

8. A collapsible form of the type described comprising parallel base boards,

side walls separable therefrom, a top wall supported by and between said side walls and slidable longitudinally of the side walls and collapsible spreaders which project over said base boards and brace said side walls against inward collapse.

9. A collapsible form of the type described comprising parallel base boards having longitudinal rails along their inner edges, side walls mounted on casters and supported on said base boards and a top wall supported by and between said side walls and having elements about which the side walls fulcrum in the collapse of the form.

10. A collapsible form of the type described comprising parallel base boards having upwardly projecting plates at their sides, parallel side walls separably supported on said base boards, said plates overlapping said side walls, separable and collapsible spreaders which project over the base boards and brace said side walls against inward collapse and a top wall supported by and between said side walls.

In testimony whereof I aflix my signature in presence of two witnesses.

FRANK J. BULL.

Witnesses:

Jnss J. JONES, B. WV. JONES.

Gopies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

